After a poultry carcass has been decapitated and eviscerated by opening the vent of the bird and removing the heart, liver, intestines, lungs and other viscera from the bird, it is necessary to remove the crop and gullet and possibly some remaining viscera from the bird. This can be done by hand, but in recent years automated equipment has been developed for removing the crop, etc. from birds.
The automated equipment in common use at the present time which is used for the removal of the crops of birds comprises a rotary machine placed in the overhead conveyor line of a poultry processing plant. The conveyor line rotates an outer turret of the machine about an inner stationary support frame, and as the birds are moved in an arcuate path about the turret, probes mounted at the circumference of the turret revolve with the turret and move downwardly into the previously opened vents of the birds, and downwardly through the neck opening of the birds and pull the crops and other viscera with them as they move out of the neck openings. The probes usually are rotated during its downward movement, and the heads of the probes include teeth or other protrusions that tend to gather the crop, etc. during the rotational movement.
After the crop has been pulled as described above, the probes are then retracted in an upward direction so that the probe heads are withdrawn back through the bird before the bird moves with the conveyor line away from the machine. U.S. Pat. No. 4,610,050 discloses a crop removal machine of this general type.
During the operation of a crop removal machine, it is desirable to cause each probe that removes the crop from the bird to reciprocate along its length in upward and downward directions, and also to rotate as it reciprocates, so that each probe can move downwardly through the body of the bird and rotate during its downward movement so as to gather and then expel the crop, etc. from the bird. This is accomplished as the probe is revolving about the peripheral portion of the rotary turret mounted on the support frame of the machine.
While the prior art poultry crop removal machines generally have included gears and other components that accomplish the reciprocating and rotary motions of the probes moving with the rotary turret of the machine, the prior art machines comprise rather complex gear assemblies and related driving components for each probe and the machines are somewhat expensive to construct and to assemble.